/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.dtr.zxing.camera;

import android.content.Context;
import android.graphics.Point;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.Size;
import android.os.Handler;
import android.util.Log;
import android.view.SurfaceHolder;

import com.dtr.zxing.camera.open.OpenCameraInterface;

import java.io.IOException;

/**
 * This object wraps the Camera service object and expects to be the only one
 * talking to it. The implementation encapsulates the steps needed to take
 * preview-sized images, which are used for both preview and decoding.
 * 
 * @author dswitkin@google.com (Daniel Switkin)
 */
public class CameraManager {

    private static final String TAG = CameraManager.class.getSimpleName();

    private final Context context;
    private final CameraConfigurationManager configManager;
    private Camera camera;
    private AutoFocusManager autoFocusManager;
    private Parameters parameter;

    private boolean initialized;
    private boolean previewing;
    private int requestedCameraId = -1;
    /**
     * Preview frames are delivered here, which we pass on to the registered
     * handler. Make sure to clear the handler so it will only receive one
     * message.
     */
    private final PreviewCallback previewCallback;

    public CameraManager(Context context) {
	this.context = context;
	this.configManager = new CameraConfigurationManager(context);
	previewCallback = new PreviewCallback(configManager);
    }

    /**
     * Opens the camera driver and initializes the hardware parameters.
     * 
     * @param holder
     *            The surface object which the camera will draw preview frames
     *            into.
     * @throws java.io.IOException
     *             Indicates the camera driver failed to open.
     */
    public synchronized void openDriver(SurfaceHolder holder)
	    throws IOException {
	Camera theCamera = camera;
	if (theCamera == null) {

	    if (requestedCameraId >= 0) {
		theCamera = OpenCameraInterface.open(requestedCameraId);
	    } else {
		theCamera = OpenCameraInterface.open();
	    }

	    if (theCamera == null) {
		throw new IOException();
	    }
	    camera = theCamera;
	}
	theCamera.setPreviewDisplay(holder);

	if (!initialized) {
	    initialized = true;
	    configManager.initFromCameraParameters(theCamera);
	}

	Camera.Parameters parameters = theCamera.getParameters();
	String parametersFlattened = parameters == null ? null : parameters
		.flatten(); // Save
			    // these,
			    // temporarily
	try {
	    configManager.setDesiredCameraParameters(theCamera, false);
	} catch (RuntimeException re) {
	    // Driver failed
	    Log.w(TAG,
		    "Camera rejected parameters. Setting only minimal safe-mode parameters");
	    Log.i(TAG, "Resetting to saved camera params: "
		    + parametersFlattened);
	    // Reset:
	    if (parametersFlattened != null) {
		parameters = theCamera.getParameters();
		parameters.unflatten(parametersFlattened);
		try {
		    theCamera.setParameters(parameters);
		    configManager.setDesiredCameraParameters(theCamera, true);
		} catch (RuntimeException re2) {
		    // Well, darn. Give up
		    Log.w(TAG,
			    "Camera rejected even safe-mode parameters! No configuration");
		}
	    }
	}

    }

    public synchronized boolean isOpen() {
	return camera != null;
    }

    /**
     * Closes the camera driver if still in use.
     */
    public synchronized void closeDriver() {
	if (camera != null) {
	    camera.release();
	    camera = null;
	    // Make sure to clear these each time we close the camera, so that
	    // any scanning rect
	    // requested by intent is forgotten.
	}
    }

    /**
     * Asks the camera hardware to begin drawing preview frames to the screen.
     */
    public synchronized void startPreview() {
	Camera theCamera = camera;
	if (theCamera != null && !previewing) {
	    theCamera.startPreview();
	    previewing = true;
	    autoFocusManager = new AutoFocusManager(context, camera);
	}
    }

    /**
     * Tells the camera to stop drawing preview frames.
     */
    public synchronized void stopPreview() {
	if (autoFocusManager != null) {
	    autoFocusManager.stop();
	    autoFocusManager = null;
	}
	if (camera != null && previewing) {
	    camera.stopPreview();
	    previewCallback.setHandler(null, 0);
	    previewing = false;
	}
    }

    /**
     * A single preview frame will be returned to the handler supplied. The data
     * will arrive as byte[] in the message.obj field, with width and height
     * encoded as message.arg1 and message.arg2, respectively.
     * 
     * @param handler
     *            The handler to send the message to.
     * @param message
     *            The what field of the message to be sent.
     */
    public synchronized void requestPreviewFrame(Handler handler, int message) {
	Camera theCamera = camera;
	if (theCamera != null && previewing) {
	    previewCallback.setHandler(handler, message);
	    theCamera.setOneShotPreviewCallback(previewCallback);
	}
    }

    /**
     * Allows third party apps to specify the camera ID, rather than determine
     * it automatically based on available cameras and their orientation.
     * 
     * @param cameraId
     *            camera ID of the camera to use. A negative value means
     *            "no preference".
     */
    public synchronized void setManualCameraId(int cameraId) {
	requestedCameraId = cameraId;
    }

    /**
     * 获取相机分辨率
     * 
     * @return
     */
    public Point getCameraResolution() {
	return configManager.getCameraResolution();
    }

    public Size getPreviewSize() {
	if (null != camera) {
	    return camera.getParameters().getPreviewSize();
	}
	return null;
    }

    public void openLight() {
	if (camera != null) {
	    parameter = camera.getParameters();
	    parameter.setFlashMode(Parameters.FLASH_MODE_TORCH);
	    camera.setParameters(parameter);
	}
    }

    public void offLight() {
	if (camera != null) {
	    parameter = camera.getParameters();
	    parameter.setFlashMode(Parameters.FLASH_MODE_OFF);
	    camera.setParameters(parameter);
	}
    }
}
